Enter a site and see which advertising and tracking code its front page actually
carries. We fetch the page once, read the source, and also look at its
ads.txt and robots.txt — because for AdSense the file is
half the answer: without it Google has no authorisation to sell that inventory.
Enter a site name to begin.
A source check is not a browser. We fetch the HTML and read it; we do not run JavaScript, set cookies or accept consent. So a tag that a Tag Manager container injects at runtime, or one that loads only after a visitor agrees to cookies, will not appear here even though it does load for real visitors. Treat the result as "what a crawler sees", which is exactly what Google's own ad crawler sees when it verifies a site.
AdSense in particular. A working setup has three parts: the AdSense
script on the page, a publisher ID (ca-pub-…) that matches the account,
and an ads.txt line that authorises Google to sell your inventory. The
report above names each of them, and says which is missing. Automatic ads can also be
verified by a google-adsense-account meta tag instead of the script.
What we do with the page. One request for the HTML, one for
ads.txt, one for robots.txt — no JavaScript, no cookie jar,
no follow-up crawl, and the result is cached for fifteen minutes. Only public sites on
ports 80 and 443 can be checked, and every redirect is checked again before it is
followed, so this cannot be pointed at a private address or used as a port scanner.
The same fetch, from other angles: DNS, HTTP and TLS checks, what sites can see about you, and alerts when a host's setup changes.